Relatively recent excursions have included Oceana--islands from the Galapagos to the Hawaiians, from the Caribbean to Australia and New Zealand, from Fiji to Micronesia and the Northern Marianas Pacific islands.
Micronesia has the historic Truk Lagoon (now the state is renamed "Chuuk" where Operation Hailstorm sank the Japanese Imperial fleet in the world's largest lagoon, 1000 square miles, fifty years ago.) The Marianas Trench, the world's deepest ocean, (the depths would swallow Everest without a ripple), separates the Pacific Ocean from the Philippine Sea. It is at Saipan that some of the last of World War II's bloodiest amphibious invasions took place with the Japanese suicide cliffs behind the beaches stormed by the US Marines. It is also from Tinian, along the Marianas Trench, that the Enola Gay took off enroute to Hiroshima, opening a new era in world horror 51 years ago. In each of the islands I have explored the land, but also the waters around the islands, on, in and under.